Why do standard size pedals sound better than mini?

[nashville]

Hello

I'm a guitarist in Nashville. I try to be unbiased about gear and just listen to the sound, but lately something has been bugging me.

Every mini size pedal that I've played through doesn't sound as good as its normal size counterpart. I don't really want this to be the case, I'd love to save room on my board, but over and over I hear the smaller pedals sounding thinner and more harsh. Not by a huge margin, but enough to make me less comfortable.

Some examples off the top of my head:
Way Huge Aqua Puss Smalls sounds harsher than an Aqua Puss mkii
MXR Carbon Copy Mini sounds thinner than a Carbon Copy
MXR Phase 95 sounds thinner than a stock or R28 mod block Phase 90
Wampler Ego Comp Mini sounds less natural than an Ego Comp
Ibanez Analog Delay Mini sounds worse than an AD9

Why do you think this would be the case?

[EBK]

I can't speak to the specific pedals you mentioned, but sometimes corners are cut to shrink a pedal down.  It could be a buffer that gets removed or a filtering stage that gets left out, for instance.  Sometimes, there isn't room for extra controls, so those features get cut too.

And, welcome to the forum!

[Mark Hammer]

1) Probably best to engage in a blind test before drawing strong inferences.  I'm not saying you're wrong, just that expectations are a big part of how we perceive things, and it's best to take steps to rule out such expectations.

2) Assuming that you ARE correct, there are any number of factors that might yield such seeming differences.  Most mini pedals use surface-mount components. But then a lot of full-sized pedals do as well.  Do full-sized pedals permit thicker/wider traces linking components, that provide lower linear resistances?  Possibly, but unlikely to be lower resistance than the much shorter trace lengths in mini pedals.  Do the electrolytic caps used in mini pedals somehow shave off low-frequency content?  Maybe, but then if surface mount is also used for full-sized pedals, it should affect them too.  So I'm stumped.  Let's hear what others have to say.

[bool]

I can confirm this to be true even in DIY builds. I recently built a buffer for my personal practice use, a SMD replica of what I use for recording, where I use nice caps, resistors, etc.

In SMD, with exactly same component values, I used mostly 1206 size parts, occasional 0805, and 1% tolerance resistors. EXCEPT I used a cca. twice bigger value output cap (4u7 SMD vs 2u2 TH).

Result? Thinner harsher variant of "the same circuit". Good enough for practice but no can do for tracking.

But hey, a blind test?
https://www.youtube.com/watch?v=V83JR2IoI8k

[amz-fx]

Every mini size pedal that I've played through doesn't sound as good as its normal size counterpart.
...
Why do you think this would be the case?

We cannot lump all smt parts into one bin and evaluate them and compare to through-hole parts since construction and quality varies in both types. A quarter-watt metal film through-hole resistor will sound different than a quarter-watt carbon film through-hole or carbon composition resistors. The same is true of smt parts - there are thick film and thin film smt resistors with different characteristics and the smaller sizes are usually more noisy than the larger smt sizes.

Dave Hill of Crane Song shared some real world measurements of resistors which clearly shows that there is a difference in performance between smt types vs through-hole. For the most part, smt resistors are slightly more noisy than through-hole versions unless you are using special very high quality smt resistors.

Also, capacitor type/construction can play a big part in the sound. The X5R or X7R ceramics are not suited for use directly in the audio path, and their actual values may fall when subject to a dc bias... the typical +4.5v bias could cause a 20% loss in capacitance, for example.   http://www.ecnmag.com/the-effect-of-dc-bias-on-mlcc-class-2-capacitors/

I would guess that most pedal builders are using whatever capacitors their smt assembler has in stock... and the MLCC X5R and X7R are usually the cheapest, or at least cheaper than C0G types. The same goes for resistors... is the pedalmaker specifying that only RCD or Susumu smt resistors be used? Hardly.

So, can there be a difference in small pedals made with smt parts vs. larger pedals using through hole components? Definitely, and some dedicated tone aficionados can hear the difference. For the rest of us... the minor difference in noise or distortion may be hard to hear.   

Best regards, Jack

[R.G.]

I'm with Mark. There >might< be differences, but the human mind's built in biases make any non-blind listening tests vastly unreliable. It is nearly impossible for humans to not be biased in simple tests where the person is doing the swapping of alternatives.

It's hard to come up with a single set of things that make all micro pedals "sound worse". As noted, maybe there are shortcuts taken in making them smaller - but ALL of them? Maybe SMD parts - but SMD is widely used in the big pedals too. Tiny traces? Even a 0.01" trace is a trivial resistance compared to what it's in series with, way smaller than even the variation due to tolerance of what it connects. Parasitic capacitances from the circuits/layout just being more compact? Maybe, but ALL of them?

These are all possible. But Occam's Razor says that it's more likely to be human perception/bias. We know that affects 100% of all pedal evaluations.

[vigilante397]

Firstly, welcome to the forum

Secondly, I'm going to have to agree with Mark, Jack, and R.G. (as I always tend to). You need to do a blind test. As a builder I switched over to 100% SMD about a year ago and have zero regrets. And frankly I have had zero complaints from my customers regarding the tone of my pedals. I built an SMD Big Muff a little while back and the gentleman I built it for says he likes it better than his vintage 70s BMP.

That being said, there is something to a couple of the pedals you're talking about, namely that the circuit may have changed, parts from older designs may have gone obsolete resulting in replacements that may not sound the same, etc.

- There were about 20 years between the original Aqua Puss and the mkii, and if they didn't change the circuit they probably would have just called it the Aqua Puss reissue. Mkii implies changes.
- While the Carbon Comp Mini isn't advertised as a different version, it was designed more than 10 years after the original.
- The Phase 95 is advertised as a combination of the Phase 45 and phase 90, both of which were designed 40 or so years ago.
- Between the Ego Comp and Ego Comp Mini some of the knobs have been replaced with switches of similar function, so it's difficult if impossible to do a 1:1 comparison of tone, you may have just been using different settings.
- One comment with the AD-9, especially if comparing newer versions to older versions, the originals had individual bias trimpots for each chip allowing the ideal tone to be dialed in, whereas this luxury was omitted on reissues, and likely on the mini as well.

Again I will defend SMD out of a personal taste for it, but as I said I have never had any complaints on my SMD builds of classic pedals.

[R.G.]

Of course, given that I personally dislike mini-micro pedals, and that all of the pedals I might have an interest in are full size, what I OUGHT to say is that absolutely, mini-micros will always sound worse because SMD is [insert favorite prejudices and beliefs here] and that [insert this or that opinionated but untested "expert" here] says they sound worse, or that quantum effects begin to dominate electromagnetic effects as size becomes smaller and that the Heisenberg Uncertainty Principle starts introducing more quantum noise as component size and traces get smaller, or that micro-stray capacitive and inductive effects begin to predominate when pedals are manufactured on days of a NOT full moon because the photino flux from nuclear processes in the sun are blocked by the moon being in the way, or ...

Yep, that's what I ought to say if I had any sense for my own self interest.   

[stallik]

Claustrophobic components

[marcelomd]

I'm not picking on anyone, but I always wonder if these differences between versions/series/vintages would show up in two units of the same item of the same batch.

[Mark Hammer]

What I'll add to the discussion is that I find a great many comparisons I run into, on-line, are not only not blind, but are between a single unit representing one class and a single unit representing another.

Back in my teaching days, when I wanted to provide a better sense of how statistical sampling works, I'd ask two students in the class to come to the front.  I'd hand them each an envelope with the same number of slips of paper in them.  I'd ask them to pull out 4 slips from their respective envelopes, and write the number they found on the blackboard.  Then I'd ask the class "If these numbers represented data from two groups, whether they were men and women, people of one political belief and a different one, rats receiving drug X and rats receiving no drug, etc., would you say these are different?"  The class would generally nod their heads, because the numbers were indeed mostly different.  "Okay", I'd say, "Take out four more slips of paper and write down what you got".  We'd repeat this cycle a few more times until the envelopes were emptied, and the class saw that the two envelopes actually contained the exact same numbers.  Their contents were identical, but drawing a very limited sample portrayed them as different, when they really weren't.  I hope the resentment they felt at being duped made the lesson sink in.

Use of a single exemplar or datapoint for any sort of pedal-to-pedal comparison is risky for drawing strong inferences.  This is especially true given the often wide tolerances in many components.  Caps, resistors (though less so), and pots can all be different from each other, despite what's printed on them and who you bought them from.  There is always the possibility that a small sample yields an accurate measure (my students could have picked the exact same 4 numbers from the envelope, first time out), but reliability of measurement is always increased by having more data points, whether we're talking opinion polling, medical research data, or pedal-to-pedal comparisons.  Your inferences/perceptions MIGHT be accurate, but there is the risk you are being misled in your perceptions by something either psychological or random component-tolerance differences.  The question one always needs to ask is "Is it just this one that sounds different in such a way, or do ALL units of this type show the same difference?".  That concern would be true if one is doing blind A/B testing or not.

Several years back, I posted a quote from Mike Matthews from an interview he gave to a business magazine.  He said that in the early days, you could take any four consecutive Big Muff Pis off the production line, and they would all sound different from each other.  Admittedly, component tolerances have tightened a lot since those days, but they still exist.

As for me, as a user I don't dislike mini-pedals, but I sure as hell hate building them.

[MaxPower]

Heat. Smaller enclosure, components closer together means they get warmer. Heat messes with biasing, resistance, hfe, etc. Throw the minis in the fridge and they'll warm up.

If that doesn't work throw them in the incinerator and they'll be sure to warm up.

[Rixen]

micro pedals contain the residual frustration of the designer...

[R.G.]

What I'll add to the discussion is that I find a great many comparisons I run into, on-line, are not only not blind, but are between a single unit representing one class and a single unit representing another.

Back in my teaching days, when I wanted to provide a better sense of how statistical sampling works, I'd ask two students in the class to come to the front.  I'd hand them each an envelope with the same number of slips of paper in them.  I'd ask them to pull out 4 slips from their respective envelopes, and write the number they found on the blackboard.  Then I'd ask the class "If these numbers represented data from two groups, whether they were men and women, people of one political belief and a different one, rats receiving drug X and rats receiving no drug, etc., would you say these are different?" [...]

Mark, again I am in awe of your ability to bring an abstract concept down to perceptible human experience. I would have hated "Engineering Statistics" a dramatic amount less if the prof had used something similar for the first or second lecture.

[vortex]

Mini pedals suffer from MBA disease.

Marketing dept. decides that Mini format is an essential feature. Design gets reworked and manufactured as cheaply as possible.

If you showed an MBA a green matchbox with "TS808" written on it, they would lose their minds.....

[bool]

I'm not sure it's all due to tolerances and component "closeness" (crosstalk etc) with SMD.

There is something distinct about SMD "sound" that personally hear in my builds, and is different to a "test" TH build with say TH X7R mlcc caps. I can't say anything about an exact "science" of SMD "sound" except that I personally dislike it.

A ratnest TH proto build of the same circuit "schematic", even with not-so-stellar components (but measured for tolerances !!), sounds more real, more to the expectations of my ears. I can't speak for anybody else, of course. Switch it A/B, easy to hear the diff. Flat and boring compared to TH.

Simple circuits with 1206 SMD parts are easy to prototype though...

[Mark Hammer]

I don't get the distaste for SMD.  I mean, I get why it is unappealing and frustrating to those of us who like to make and/or mod things.  But there are SO many popular and well-respected pedals of a variety of sizes that rely on SMD.  I don't hear folks complaining about those pedals, that they sound weak, or harsh, or thin.  People just say how fantastic they sound, and the pedal sells thousands or more.  I wouldn't doubt that a great many Nashville studio folks have plenty of SMD-based pedals in their arsenal, are quite happy with them, and get gigs because of the quality of their tone.

I am NOT disagreeing with the suggestion others here have made that a company would cut corners in design to still turn a profit. It's a business that is increasingly competitive and trying to cater to the expectation that pedal-makers should hand the world to consumers on a $50 platter.  With so much saturation of the market, all of those trying to cater to the "economy" niche have to look for ways to scratch out a few more yuan.  I have posted numerous times in past about the literal corners cut in the manufacture of smaller practice/student amps, where tone and volume is sacrificed in order to reduce manufacture, shipping, storage, and packaging costs of such small amps.  Many could sound a LOT better if the cab was just a little bit deeper and wider.  But you can't make any money on them by spending more on wood, having a heavier and larger product to ship and purchase boxes for, and find warehouse shelf space for, etc. etc. 

Does that same concern apply to mini-pedals?  I think not.  Perhaps such pedals might employ cheaper footswitches or jacks, but the required circuitry can generally all fit in there with ease.  I started a thread here earlier this summer regarding the difference in quality and lifespan between traditional 24mm pots and smaller ones, like the 9mm mini pots used in mini-pedals (and a lot of 1590BB-sized units as well), and was schooled that more-than-acceptable quality can be found at any size.  So one could not attribute any difference in sound quality to smaller pots in small pedals in any blanket/wholesale fashion.  As for heat and heat dissipation, get back to me when mini-pedals start using tubes or drawing 200ma.  Heck, if anything, situating the circuitry closer to the chassis in mini-pedals ought to result in better heat dissipation.

[EBK]

Heck, if anything, situating the circuitry closer to the chassis in mini-pedals ought to result in better heat dissipation.

That's the only part of what you said that I disagree with.    I would think that larger thermally conductive surface area of a bigger enclosure would win versus the smaller thickness of the air envelope inside the miniature enclosure. 
Buy, yes, if the pedal is getting hot, we have other more pressing matters to discuss, so I agree it is a non-issue. 

[Mark Hammer]

Depends on how much heat there is to dissipate.  If it's a lot, then more aluminum certainly IS better than less. 

I've posted here before about the repair I did to a Diamond Memory Lane earlier this year.  After a few e-mail exchanges I had with their tech support, the tech guy remembered that, on an early run of the ML, their parts supplier had sent them a batch of TO-220-sized regulators with thinner-than-spec heat fins.  The three different voltage regulators in the unit are free-standing and not thermally-coupled to anything, hence relying on the capacity of the heat fins alone.  The two regulators with normal-thickness fins behaved just fine, but the one with the too-thin-fin overheated after about 10 minutes of use and drifted off spec, resulting in an annoying whine from the pedal.  Replacement with a proper-thickness regulator completely fixed the problem.

But if a pedal draws 40ma it's hard to see how being thermally coupled to the wall of a 1590DD or larger provides any advantage over simply being near the walls of a 1590A.  There is a point of diminishing returns.  You will note that TO-92 regulators are expected to handle 100ma and have NO heat fin, nor are they expected to be thermally coupled to anything.

[bool]

...
But there are SO many popular and well-respected pedals of a variety of sizes that rely on SMD.
...

My impression was that the OP was comparing a "classic" TH pedal vs it's "mini" SMD version. IMHO "same" circuit made with TH parts vs same cckt made with SMD.

I totally get that a circuit developed for SMD manufacture from the get-go will in the end have to "sound good" or it will flop (but we never know how it was when it started in presumably breadbord TH tech). The makers will no doubt tweak it.

OTOH. I have also some first hand (ear??) experience with TH-SMD translation and am not such a fan when it comes to audio. Everything seems to sound more "be-x-ringer" if you know what I mean.